1. Field of Invention
This invention relates to sheaths or introducers. More particularly, this invention relates a guiding introducer system for mapping and ablation procedures in the left ventricle of the human heart.
2. Prior Art
Introducers and catheters have been in use for medical procedures for many years. For example, catheters have been used to convey an electrical stimulus to a selected location within the human body. Another use is monitoring and making measurements for diagnostic tests within the human body. Catheters are also used by physicians to examine, diagnose and treat while positioned at a specific location within the body which is otherwise inaccessible without more invasive procedures. In use, catheters are inserted into a major vein or artery which is near the body surface. These catheters are then guided to the specific location for examination, diagnosis or treatment by manipulating the catheter through the artery or vein of the human body.
Catheters have become increasingly useful in remote and difficult to reach locations within the body. However, the utilization of these catheters is frequently limited because of the need for the precise placement of the electrodes of the catheter at a specific location within the body.
Control of the movement of catheters to achieve such precise placement is difficult because of the inherent structure of a catheter. The body of a conventional catheter is long and tubular. To provide sufficient control of the movement of the catheter, it is necessary that its structure be somewhat rigid. However, the catheter must not be so rigid as to prevent the bending or curving necessary for movement through the vein, artery or other body part to arrive at the specified location. Further, the catheter must not be so rigid as to cause damage to the artery or vein while it is being moved within the body.
While it is important that the catheter not be so rigid as to cause injury, it is also important that there be sufficient rigidity in the catheter to accommodate torque control, i.e., the ability to transmit a twisting force along the length of the catheter. Sufficient torque control enables controlled maneuverability of the catheter by the application of a twisting force at the proximal end of the catheter that is transmitted along the catheter to its distal end. The need for greater torque control often conflicts with the need for reduced rigidity to prevent injury to the body vessel.
Catheters are used increasingly for medical procedures involving the human heart. In these procedures a catheter is typically advanced to the heart through veins or arteries and then is positioned at a specified location within the heart. Typically, the catheter is inserted in an artery or vein in the leg, neck, upper chest or arm of the patient and threaded, generally with the aid of a guidewire and conventional introducer, through various arteries or veins until the tip of the catheter reaches the desired location in the heart.
The distal end of a catheter used in such a procedure is sometimes preformed into a desired curvature so that by torquing the catheter about its longitudinal axis, the catheter can be manipulated to the desired location within the heart or in the arteries or veins associated with the heart. For example, U.S. Pat. No. 4,882,777 discloses a catheter with a complex curvature at its distal end for use in a specific procedure in the right ventricle of a human heart. U.S. Pat. No. 5,231,994 discloses a guide catheter for guiding a balloon catheter for the dilation of coronary arteries. U.S. Pat. No. 4,117,836 discloses a catheter for the selective coronary angiography of the left coronary artery and U.S. Pat. Nos. 5,299,574, 5,215,540, 5,016,640 and 4,883,058 disclose catheters for selective coronary angiography of the right coronary artery.
Conventionally, angiographic or balloon catheters are guided to the particular location within the heart, such as the coronary arteries, by use of a guidewire. During this procedure, the guidewire is first introduced into the vein or artery and is then advanced through the vasculature to the particular coronary artery to be analyzed. The catheter is then directed over the guidewire to the particular coronary artery. A conventional short straight introducer is often used to assist in introducing the coronary catheter into the vasculature, but is not used for advancing the coronary catheter through the vasculature to the coronary artery.
U.S. Pat. No. 5,242,441 discloses a deflectable catheter for ablation procedures in the ventricular chamber. See also U.S. Pat. No. 4,033,331. In addition, U.S. Pat. No. 4,898,591 discloses a catheter with inner and outer layers containing braided portions. The '591 patent also discloses a number of different curvatures for intravascular catheters.
Thus, catheters with predetermined shapes, designed for use during specific medical procedures generally associated with the heart or the vascular system have been disclosed.
In addition to single catheters with various curvatures, U.S. Pat. No. 4,581,017 discloses an inner and outer guide catheter, numbers 138 and 132, for use with a balloon catheter for treatment of coronary arteries. U.S. Pat. No. 5,120,323 discloses a guide catheter system for use in coronary arteries comprising an outer guide catheter (12) and a telescoping guide catheter (26), neither of which are precurved. U.S. Pat. No. 5,267,982 discloses a catheter assembly and methods for catheterization of coronary arteries wherein an inner catheter (50) and outer catheter (52) are used in combination for the treatment of right and left coronary angiographic procedures. See also U.S. Pat. No. 4,935,017 which discloses a similar device. U.S. Pat. No. 5,290,229 discloses a straight outer sheath and a preformed inner catheter for use in the heart. See also U.S. Pat. Nos. 5,304,131, 4,810,244 and 5,279,546.
U.S. Pat. No. 5,476,495 discloses a shaped guide sheath (166) for use in the right ventricle for ablation procedures.
Ablation procedures in the heart using a single, straight guide sheath have been disclosed. For example, catheter ablation of accessory pathways using a long vascular sheath by means of a transseptal or retrograde approach is discussed in Saul, J. P., et al. “Catheter Ablation of Accessory Atrioventricular Pathways in Young Patients: Use of long vascular sheaths, the transseptal approach and a retrograde left posterior parallel approach” J. Amer. Coll. Card., Vol. 21, no. 3, pps 571–583 (Mar. 1, 1993). See also Swartz, J. F. “Radiofrequency Endocardial Catheter Ablation of Accessory Atrioventricular Pathway Atrial Insertion Sites” Circulation, Vol. 87, no. 2, pps. 487–499 (February, 1993).
In addition, U.S. Pat. No. 5,427,119 discloses a shaped guiding introducer for introduction of an ablation and mapping catheter into the right atrium for the treatment of specific cardiac arrhythmia. U.S. Pat. No. 5,497,774 discloses the use of a guiding introducer for introduction of an ablation and mapping catheter into the left atrium for the treatment of specific cardiac arrhythmia.
U.S. Pat. No. 4,641,649 discloses the use of high frequency energy for the treatment of tachycardia or cardiac dysrhythmia. See also U.S. Pat. Nos. 5,246,438 and 4,945,912, which disclose the use of radio frequency energy for ablation of cardiac tissue. In addition, various articles have disclosed the ablation of specific locations within the heart by use of energy, in particular, radio frequency energy. See, for example, Gallagher, J. J. et al. “Catheter Technique for Closed-Chest Ablation of the Atrioventricular Conduction System” N. Engl. J. Med. Vol. 306, pp. 194–200 (1982); Horowitz, L. N. “Current Management of Arrhythmia” pp. 373–378 (1991); Falk, R. H. et al. “Atrial Fibrillation Mechanics and Management” pp. 359–374 (1992); and Singer, I. “Clinical Manual of Electrophysiology” pp. 421–431 (1993).
In addition, U.S. Pat. No. 5,172,699 discloses a general process for the identification and ablation of ventricular tachycardia sites. See also U.S. Pat. Nos. 5,222,501 and 5,242,441.
In addition, the use of radio frequency ablation energy for the treatment of Wolff-Parkinson-White Syndrome in the left atrium by use of a transseptal sheath is disclosed in Swartz, J. F. et al. “Radiofrequency Endocardial Catheter Ablation of Accessory Atrioventricular Pathway Atrial Insertion Sites” Circulation 87:487–499 (1993). See also Tracey, C. N. “Radio Frequency Catheter Ablation of Ectopic Atrial Tachycardia Using Paced Activation Sequence Mapping” J. Am. Coll. Cardiol. 21:910–917 (1993).
While a number of references have disclosed ablation procedures in the heart utilizing sheaths and catheters, there is still a need for new methods for the introduction of ablation catheters to specific locations in the heart, including specifically the left ventricle.
Accordingly, it is an object of this invention to disclose a guiding introducer system for selected medical procedures associated with the left ventricle of the human heart.
It is a further object of this invention to disclose a guiding introducer system for use in selected electrophysiology procedures associated with the left ventricle of the human heart.
Another object of this invention is to disclose a guiding introducer system for use in selected ablation procedures associated with the left ventricle of the heart.
It is a still further object of this invention to disclose a guiding introducer system for use in the selected ablation of sites associated with the mitral valve from the ventricular side for the treatment of left ventricular tachycardia.
These and other objects are obtained by the design of the guiding introducer system disclosed in the instant invention.